Administrator Guide

AAA Authentication
Dell EMC Networking OS supports a distributed client/server system implemented through authentication, authorization, and accounting
(AAA) to help secure networks against unauthorized access.
In the Dell EMC Networking implementation, the Dell EMC Networking system acts as a RADIUS or TACACS+ client and sends
authentication requests to a central remote authentication dial-in service (RADIUS) or Terminal access controller access control system
plus (TACACS+) server that contains all user authentication and network service access information.
Dell EMC Networking uses local usernames/passwords (stored on the Dell EMC Networking system) or AAA for login authentication. With
AAA, you can specify the security protocol or mechanism for different login methods and different users. In Dell EMC Networking OS, AAA
uses a list of authentication methods, called method lists, to define the types of authentication and the sequence in which they are applied.
You can define a method list or use the default method list. User-defined method lists take precedence over the default method list.
NOTE: If a console user logs in with RADIUS authentication, the privilege level is applied from the RADIUS server if the
privilege level is configured for that user in RADIUS, whether you configure RADIUS authorization.
NOTE: RADIUS and TACACS servers support VRF-awareness functionality. You can create RADIUS and TACACS groups
and then map multiple servers to a group. The group to which you map multiple servers is bound to a single VRF.
Configuration Task List for AAA Authentication
The following sections provide the configuration tasks.
• Configuring AAA Authentication Login Methods
• Enabling AAA Authentication
• Enabling AAA Authentication - RADIUS
For a complete list of all commands related to login authentication, refer to the Security chapter in the Dell EMC Networking OS
Command Reference Guide.
Configure Login Authentication for Terminal Lines
You can assign up to five authentication methods to a method list. Dell EMC Networking OS evaluates the methods in the order in which
you enter them in each list.
If the first method list does not respond or returns an error, Dell EMC Networking OS applies the next method list until the user either
passes or fails the authentication. If the user fails a method list, Dell EMC Networking OS does not apply the next method list.
Configuring AAA Authentication Login Methods
To configure an authentication method and method list, use the following commands.
Dell EMC Networking OS Behavior: If you use a method list on the console port in which RADIUS or TACACS is the last authentication
method, and the server is not reachable, Dell EMC Networking OS allows access even though the username and password credentials
cannot be verified. Only the console port behaves this way, and does so to ensure that users are not locked out of the system if network-
wide issue prevents access to these servers.
1. Define an authentication method-list (method-list-name) or specify the default.
CONFIGURATION mode
aaa authentication login {method-list-name | default} method1 [... method4]
The default method-list is applied to all terminal lines.
Possible methods are:
• enable: use the password you defined using the enable secret, enable password, or enable sha256-password
command in CONFIGURATION mode. In general, the enable secret command overrules the enable password command.
If you configure the enable sha256-password command, it overrules both the enable secret and enable password
commands.
• line: use the password you defined using the password command in LINE mode.
• local: use the username/password database defined in the local configuration.
• none: no authentication.
• radius: use the RADIUS servers configured with the radius-server host command.
• tacacs+: use the TACACS+ servers configured with the tacacs-server host command.
2. Enter LINE mode.
Security
755